Some exception benchmarks and tests

microbenchmarks/exceptions_ubench.py

+def f():
+    # Try to eliminate as much non-exception stuff as possible:
+    from __builtin__ import Exception
+    e = Exception()
+
+    for i in xrange(100000):
+        try:
+            raise e
+        except Exception:
+            pass
+f()

test/bench_exceptions.cpp

+#include <vector>
+#include <cstdio>
+#include "stdint.h"
+
+struct ExcInfo {
+    int64_t a, b, c;
+};
+
+void bench0() {
+    int64_t t = 0;
+    for (int i = 0; i < 1000000; i++) {
+        try {
+            throw 0;
+        } catch (int x) {
+        }
+    }
+    printf("%ld\n", t);
+}
+
+void bench1() {
+    int64_t t = 1;
+    for (int i = 0; i < 1000000; i++) {
+        try {
+            throw ExcInfo({.a=t, .b=t, .c=t});
+        } catch (ExcInfo e) {
+            t += e.a + e.b + e.c;
+        }
+    }
+    printf("b1 %ld\n", t);
+}
+
+static __thread ExcInfo curexc;
+struct ExceptionOccurred {
+};
+
+void bench2() {
+    int64_t t = 1;
+    for (int i = 0; i < 1000000; i++) {
+        try {
+            curexc.a = t;
+            curexc.b = t;
+            curexc.c = t;
+            throw ExceptionOccurred();
+        } catch (ExceptionOccurred) {
+            t += curexc.a + curexc.b + curexc.c;
+        }
+    }
+    printf("b2 %ld\n", t);
+}
+
+void rbench1() {
+    int64_t t = 1;
+    for (int i = 0; i < 1000000; i++) {
+        try {
+            try {
+                throw ExcInfo({.a=t, .b=t, .c=t});
+            } catch (ExcInfo e) {
+                throw e;
+            }
+        } catch (ExcInfo e) {
+            t += e.a + e.b + e.c;
+        }
+    }
+    printf("rb1 %ld\n", t);
+}
+
+void rbench2() {
+    int64_t t = 1;
+    for (int i = 0; i < 1000000; i++) {
+        try {
+            try {
+                curexc.a = t;
+                curexc.b = t;
+                curexc.c = t;
+                throw ExceptionOccurred();
+            } catch (ExceptionOccurred x) {
+                throw x;
+            }
+        } catch (ExceptionOccurred) {
+            t += curexc.a + curexc.b + curexc.c;
+        }
+    }
+    printf("rb2 %ld\n", t);
+}
+
+int main() {
+    bench1();
+}

test/tests/sys_excinfo.py

@@ -216,3 +216,33 @@ def f12():
         print "after next:", sys.exc_info()[0]
     list(i)
 f12()
+
+# If an exception is thrown+caught in course of exception-matching, we need to still operate on the original exception:
+def f13():
+    print
+    print "f13"
+    def inner():
+        try:
+            raise KeyError
+        except:
+            pass
+        print sys.exc_info()[0]
+        return ZeroDivisionError
+
+    # This applies to what goes into exc_info:
+    try:
+        1/0
+    except inner():
+        print sys.exc_info()[0]
+
+    # This also applies to the exception that will propagate:
+    try:
+        try:
+            raise AttributeError()
+        except inner():
+            print "shouldn't get here!"
+    except Exception, e:
+        print type(e)
+        print sys.exc_info()[0]
+f13()
+